This is the generic class for apparatus and corresponding
processes involving the generation or use of electromagnetic radiation
within the X-ray spectrum as defined above.

Methods, systems, and elements with specific features characteristic
of X-ray applications are classified herein.

Mere use with or attachment to an X-ray device or recitation
of an undefined X-ray test or analysis is insufficient to cause
classification within this class.

SECTION II - LINES WITH OTHER CLASSES AND WITHIN THIS CLASS

This class is the result of a reclassification of the X-ray art
which was extracted from several classes, principally Class 250,
Radiant Energy. The subject matter of this class is, therefore,
essentially identical in scope to the X-ray subject matter formerly
found in the more comprehensive Class 250 with the addition of the
X-ray source subject matter of Class 313, Electric Lamp and Discharge
Devices. Selected disclosures concerning elements "for use in"
but not restricted to X-ray systems were removed from the above
described body of art and placed in more appropriate classes.

Significantly claimed apparatus external to this class, claimed
in combination with apparatus under the class definition which is
used to monitor, control or otherwise effect the operation of the
external apparatus, is classified in the class appropriate to that
external apparatus.

Nominally claimed apparatus external to this class, claimed
in combination with apparatus under the class definition, is classified
in this class unless provided for in the appropriate external class.

Measuring and Testing,
subclass 23.2for the analysis of gases; particularly subclass
23.35, for the combination of a gas chromatography test and a radiation
(invisible and visible) test of the effluent from the test; subclasses
53.01+ for the examination of liquids or a liquid suspension
of solids; subclasses 73+ for moisture content or absorption
characteristics generally; subclass 104 for surface or cutlery edge
testing generally; subclasses 151+ for bore hole and drilling
study tests generally; subclasses 861+ for volume or rate
of flow meters generally; subclasses 290+ for liquid level
or depth gauges; and subclasses 570+ for ultrasonic testing.

Data Processing: Measuring, Calibrating, or Testing, appropriate subclasses for a computer data processing
system for measuring, calibrating, or testing that may include X-ray
subject matter.

SECTION IV - GLOSSARY

DETECTOR

A material or device whose response to X-ray energy is used
to indicate the presence or amount of incident radiation.

GAMMA RAY

In this class the term "gamma ray" is considered to be synonymous
with the term "X-ray". Gamma rays are usually considered to be
produced by some natural phenomenon such as the decay of an atomic
nucleus whereas X-rays are usually considered to be produced by
an electronic tube or other manufactured device.

INSPECTION OR EXAMINATION

A term implying a source of X-ray energy, and/or
means to irradiate an object by said source and a detector responsive
to X-radiation from the object to provide an indication representing
some characteristic of the object.

OBJECT OR ANALYTE

A material subjected to X-radiation for treatment or whose
response to or effect on the X-radiation is used to indicate something
about the material.

X-RAY

Electromagnetic radiation lying in a range between "cosmic
rays" and "ultraviolet rays". This range is defined as lying between
0.001 and 100 angstrom units or 10-11 and 10-6 centimeters
in wavelength.

This subclass is indented under subclass 1. Subject matter including means to spatially modulate a beam
of X-rays prior to its impinging upon an object or means to spatially demodulate
a modulated beam.

(1)Note. The spatial modulation may be produced by spatial filtering
of an unmodulated beam or by means within the X-ray source which
directly produces a modulated beam.

This subclass is indented under subclass 1. Subject matter including systems and devices such as spectrometers
employing the Mossbauer effect, i.e., the absorption or emission
of gamma rays by an atomic nucleus without the nuclear recoil that
usually accompanies such phenomena.

This subclass is indented under subclass 1. Subject matter employing computer processing of X-ray absorption
or transmission data to produce an image of a cross section of an object.

(1)Note. The devices found herein usually include some mechanism
which allows relative movement between the source or detector of
X-rays and the object being examined. The tomographic movement is
typically produced by holding the object stationary and moving the
X-ray source and the detector simultaneously in opposite directions
about a pivot point lying in a plane through the object.

This subclass is indented under subclass 4. Subject matter including irradiating an object with X-rays
or one or more specific energy levels and determining transmission
or other characteristics of the object at the one or more energy
levels.

This subclass is indented under subclass 4. Subject matter including determining the distribution in
intensity of X-rays exiting an object, the X-rays having been deviated
in direction by the object or being the result of secondary emission
from the object.

This subclass is indented under subclass 4. Subject matter including means which causes movement, other
than rotational movement, of the source or detector within the plane
of the cross section of the object being examined.

This subclass is indented under subclass 11. Subject matter including means within the source of X-rays
which causes movement of an electron beam across the X-ray target
to cause movement of the beam of X-rays.

This subclass is indented under subclass 4. Subject matter including means for electrically interfacing
the source or detector in such manner that continuous unidirectional
mechanical rotation can take place without interruption of the operation
of the source or detector.

(1)Note. Slip rings, energy storage within the rotating structure,
and telemetering signals from the rotating to the stationary structure
are typical means used in systems of this type.

This subclass is indented under subclass 4. Subject matter including means which allows the source or
detector to be positioned such that the cross section being imaged
is in some other than the more usual vertical plane.

This subclass is indented under subclass 4. Subject matter including use in the path of the X-rays of
a material whose X-ray absorption characteristics are similar to
those of the object to be examined for purposes such as path length
compensation.

(1)Note. Surrounding a human being with water is one example
of the subject matter found here.

(2)Note. This subclass also includes "examination phantoms" such
as manikins.

This subclass is indented under subclass 4. Subject matter including means for sustaining the object
under examination against gravity in a selected orientation relative
to the X-ray source or detector or means for indicating or monitoring
the position of the object relative to the apparatus.

This subclass is indented under subclass 1. Subject matter including means which produces an image of
a cross section of an object.

(1)Note. The devices found herein usually include some mechanism
which allows relative movement between the source or detector of
X-rays and the object being examined. In conventional tomography, the
tomos:graphic movement is typically produced by holding the object
stationary and moving the X-ray source and the recording medium
simultaneously in opposite directions about a pivot point lying
in a plane through the object.

(2)Note. Tomography is commonly referenced in the art by the
equivalent terms laminography, planiography, sectional radiography.

This subclass is indented under subclass 21. Subject matter including the production of a set of radiographs
which, when superimposed in a stack for viewing with the radiographs
aligned so that the images of a given point in the object all coincide,
all other points or object details in the same plane will be revealed
in an unobstructed view and images of all points lying in other
planes, even closely adjacent planes, will be obscured or blurred
out.

(1)Note. Other specific planes may be selectively viewed by
appropriate positioning of the radiographs within the stack.

(2)Note. Dynamic tomography typically utilizes a planar tomographic
movement achieved with the effective pivot point of the linkage
being disposed in a plane through the object with separate images being
recorded for each of multiple exposures which are made at different angles
through the object, i.e., a different film or other recording medium
is used for each exposure to produce the set of radiographs.

This subclass is indented under subclass 21. Subject matter wherein the source, object, and detector
of X-rays or gamma rays are arranged in such fashion that the cross
section being imaged is other than the usual longitudinal cross
section.

This subclass is indented under subclass 21. Subject matter wherein the source is moved along a path
which is nonplanar, e.g., spherical or is nonparallel to the object
plane or cross section to be imaged.

This subclass is indented under subclass 1. Subject matter including a detector upon which a latent
image in the form of a pattern of electric charges is produced by
action of x-radiation or gamma radiation.

(1)Note. The detector usually includes (a) a pair of spaced
imaging electrodes defining an imaging gap therebetween, (b) an image
receptor sheet lying within the gap between the electrodes, (c)
an imaging fluid filling the remaining space between the electrodes,
and (d) an enclosing chamber. By applying a charge across the electrodes
and ionizing the fluid through irradiation, charges will be removed
from or deposited upon the image receptor sheet.

This subclass is indented under subclass 28. Subject matter including means for displaying an image of
the object under examination at the time of exposure to radiation
in addition to or instead of the subsequent production of a hard copy
image record.

This subclass is indented under subclass 28. Subject matter wherein the electric field between the two
imaging electrodes is focused such that the paths of charged particles
traveling between the electrodes converge at the origin of the imaging
X-rays or gamma rays.

(1)Note. Focusing may be achieved by the use of cylindrically
or spherically curved imaging electrodes.

This subclass is indented under subclass 34. Subject matter restricted to the mask itself which is made
up of adjacent areas of X-ray opaque and X-ray transparent material arranged
in a selected pattern (usually of an electronic circuit) and used
for X-ray lithos:graphic production of plural copies of the pattern.

(1)Note. Although this subclass is restricted to single elements,
it is placed here in the schedule as an exception to the general
rule of hierarchy since the element described is used only in the system
of the parent subclass.

This subclass is indented under subclass 1. Subject matter including the generation, analysis, or recording
of interference patterns resulting from the interaction of plural
X-ray wavefronts or the making of optical holograms from conventional
radiographs, e.g., stereo radiography, to permit holographic display
of the information.

Optics: Systems (Including Communication) and
Elements,
subclasses 462+ for light type devices for stereoscopically viewing
X-ray stereograms or a stereoscopic record or records and optical
systems for producing a visual record taken from two different points
of view.

This subclass is indented under subclass 1. Subject matter including the collection and detection of
X-rays from distant objects (e.g., the stars) or the formation of
an image of an object, which image is substantially larger than the
object.

This subclass is indented under subclass 1. Subject matter including the measurement or analysis of
secondary X-rays resulting from the excitation by primary x-radiation
or gamma radiation of analyte atoms.

(1)Note. Although not specifically include within each of the
following definitions, fluorescence systems usually include (a) a
source of primary X-rays or gamma rays, (b) an analyte which emits
fluorescent X-rays, (c) an analyte holder or positioning means,
and (d) a detector of the fluorescent X-rays.

This subclass is indented under subclass 44. Subject matter including measurement of the chemical composition,
quantity (density), or presence of a specific substance in an analyte.

(1)Note. The measurement is typically accomplished by energy
analysis of the fluorescent X-rays emitted by the object under examination.
The energy of specific line emissions uniquely identifies chemical
elements and the intensity of the emission characterizes its quantity.

This subclass is indented under subclass 45. Subject matter including specially separating fluorescent
X-rays of different frequencies prior to determination of the intensity
thereof.

(1)Note. This subclass requires that the origin of the X-rays
being analyzed is an analyte which is excited to fluorescence by
primary X-rays, while the means for spatial energy dispersion of
X-rays of subclass 82 will function regardless of the manner of
production of the X-rays.

This subclass is indented under subclass 44. Subject matter including measurement of the thickness or
density of an object such as a sheet or coating.

(1)Note. This measurement is typically accomplished by comparing
the attenuation of fluorescent X-rays generated within the object
with the attenuation in a reference object of known thickness or density.

This subclass is indented under subclass 1. Subject matter including the measurement or analysis of
X-rays that have passed through an object under examination to determine
the attenuation or other change in X-ray characteristics resulting
from the passage.

(1)Note. Although not specifically included within each of the
following definitions, absorption systems usually include, (a) a
source of X-rays or gamma rays, (b) an object under examination, (c)
an object holder or positioning means, and (d) a detector of X-rays.

This subclass is indented under subclass 51. Subject matter which includes a body of fluent material,
an X-ray or gamma ray source, and a detector responsive to the source
arranged so that the body of fluent material is located in the radiation
path between the source and detector or the body of fluent material
supports either the source or detector, wherein the detector produces
an output representative of the height or depth of the body of fluent
material and methods corresponding to the apparatus.

This subclass is indented under subclass 51. Subject matter including measurement of the chemical composition,
quantity (density), or presence of a specific substance in an analyte.

(1)Note. The measurement is typically accomplished by energy
analysis of the X-ray spectra as absorbed by the analyte and comparing
the absorbed spectra with reference a spectra from substances of known
composition. The energy of specific line absorptions uniquely identifies chemical
elements and the degree of the absorption characterizes its quantity.

This subclass is indented under subclass 54. Subject matter including comparison of the attenuation of
X-rays passing through the object under examination with the attentuation produced
by a reference object of known thickness or density.

This subclass is indented under subclass 51. Subject matter including detection and location of a structural
defect in an object under examination by analyzing the pattern of
absorption of X-rays passing through the object in comparison with
pattern of absorption of X-rays passing through a reference object
of known integrity.

This subclass is indented under subclass 62. Subject matter including forming an image using visible
light, mechanical impression or other such technique in addition
to the image formed by using X-rays.

This subclass is indented under subclass 1. Subject matter including the measurement or sensing of X-rays,
the direction of which have been modified by interaction with an
object under examination.

(1)Note. Although not specifically included within each of the
following definitions, diffraction, reflection, or scattering systems
usually include, (a) source of X-rays or gamma rays, (b) a diffracting,
reflecting, or scattering object, (c) an object holder or positioning
means, and (d) a detector of diffracted, reflected, or scattered
X-rays.

This subclass is indented under subclass 70. Subject matter providing for the generation and examination
or determination of at least part of the characteristic X-ray diffraction
pattern of an analyte.

(1)Note. Devices under subclass 82 employ diffraction elements
such as crystals and gratings which spatially disperse X-rays according
to their energy. These elements are not objects or examination as in
this subclass but rather are tools for examining something else
since their diffraction patterns are known.

This subclass is indented under subclass 71. Subject matter including detecting the presence or measuring
the extent of stress within an analyte by analyzing the manner in
which its X-ray diffraction pattern is modified when the X-rays are
incident on a stressed area.

This subclass is indented under subclass 73. Subject matter including measuring surface features of a
crystal by analyzing the manner in which X-rays are differentially
diffracted by different areas of the surface of the crystal.

This subclass is indented under subclass 73. Subject matter in which the crystal being analyzed is piezoelectric,
i.e., becomes electrically polarized when mechanically strained
or mechanically strained when electrically polarized.

This subclass is indented under subclass 70. Subject matter including means for physically spreading
out an X-ray beam into its various energy components by diffraction,
e.g., spectrometers and monochromators.

(1)Note. This subclass includes means for spatial energy separation
of X-rays, which means function regardless of the origin or manner
of production of the X-rays.

This subclass is indented under subclass 82. Subject matter including measurement of the chemical composition,
quantity (density), or presence of a specific substance in an analyte.

(1)Note. This subclass includes means for energy analyzing X-rays
that have interacted with or have been produced by an analyte such
as by scattering or radioactive decay for the purpose of determining
analyte composition.

This subclass is indented under subclass 82. Subject matter including a specific element of its support
means for limiting the energy spectrum of a beam of X-rays to a
narrow band of energies or for converging a beam of X-rays.

(1)Note. The elements of this subclass comprise crystals and
gratings which, by diffraction, spatially disperse X-rays according
to their energy. These elements are not the objects of examination as
in subclass 71 above but rather are tools for examining something
else since their diffraction patterns are known.

This subclass is indented under subclass 86. Subject matter including measurement of the chemical composition,
quantity (density), or presence of a specific substance in an analyte.

(1)Note. The measurement is typically accomplished by deflection
analysis of the X-rays modified in direction by the analyte and
comparing the deflection with reference data from substances of known
composition.

This subclass is indented under subclass 86. Subject matter including measurement of the thickness or
density of an object such as a sheet or coating.

(1)Note. This measurement is typically accomplished by comparing
the modification in direction of X-rays as a result of their interaction
with an object under examination with the modification in direction
produced by a reference object of known thickness or density.

This subclass is indented under the class definition. Subject matter comprising a combination of electrically
connected devices for powering or controlling and connected to an
X-ray source or detector or displaying an image or other information
developed from the source or detector.

This subclass is indented under subclass 91. Subject matter wherein the source is an X-ray tube having
a movable target or electrode and at least one part of the circuit
is connected thereto to control or monitor its movement.

This subclass is indented under subclass 96. Subject matter wherein the means to determine the duration
of exposure is responsive to the amount of radiation being applied
to the object or received by the detector.

This subclass is indented under subclass 98.9. Subject matter wherein the television system includes means
for subtracting one image from another and then displaying the resultant
image so as to, for example, enhance the display of a particular
body part such as a blood vessel.

This subclass is indented under subclass 98.2. Subject matter wherein the television system includes means
for subtracting or adding one image from another and then displaying
the resultant image so as to, for example, enhance the display of
a particular body part such as a blood vessel.

This subclass is indented under subclass 98.2. Subject matter wherein the X-ray television system includes
visible light optical elements between the means for converting
the X-ray image to a visible light image and the means for converting
the visible light image to an electronic video signal.

This subclass is indented under subclass 98.2. Subject matter wherein the X-ray television system includes
electronic circuit means for modifying the video signal representative
of the X-ray image in accordance with an electronic signal representative
of the X-rays that are scattered by the imaged object or by its
surroundings.

This subclass is indented under subclass 98.2. Subject matter wherein the X-ray television system includes
means for displaying on a television monitor information in addition
to the actual X-ray image.

(1)Note. Such information may comprise positional data of the
examined object or the X-ray equipment, exposure parameters such
as X-ray tube voltage and current, the outline of a body organ or contrast
agent bolus, an EKG waveform or a visible light image of the examined object
or different colors which may represent a time lapse, composition,
or regions of interest.

This subclass is indented under subclass 98.2. Subject matter wherein the television system includes a
source of X-rays that comprises an electron tube with means to emit
a small diameter X-ray beam that is electronically scanned over
the object to be examined.

This subclass is indented under subclass 98.2. Subject matter wherein the X-ray television system includes
means for automatically adjust or maintain constant the image brightness
of the video display.

This subclass is indented under subclass 98.2. Subject matter wherein the X-ray television system includes
a solid-state detector that generates the video image in response
to the X-ray or visible light image.

This subclass is indented under subclass 91. Subject matter wherein the circuit includes specific devices
such as voltage regulators, current convertors, and rectifiers which
are used to develop the required voltages and currents for proper
operation of the X-ray or gamma ray source.

This subclass is indented under subclass 101. Subject matter including supplying appropriate voltages
and current to a source to control the focus or intensity or to
cause scanning or deflection of the X-ray producing electron beam
therein.

This subclass is indented under subclass 91. Subject matter wherein the circuit includes a detailed embodiment
of a switching circuit for controlling the operation of an X-ray
system or its components.

This subclass is indented under subclass 114. Subject matter wherein the switching means is operative
to select between different portions of the circuit, different devices
connected to the circuit or different modes of operation.

This subclass is indented under subclass 114. Subject matter wherein the switching means causes discontinuation
of operation of a portion or all of the system upon the occurrence
of an undesired condition.

This subclass is indented under subclass 119. Subject matter wherein the source is caused to emit X-rays
through excitation of a target upon bombardment of the target with
subatomic particles generated by the nuclear decay of a radioactive
substance.

This subclass is indented under subclass 121. wherein the tube includes means such as getters, regulators,
and pumps to permit variation of the vacuum within the tube or which
act continuously to maintain the vacuum, e.g., by scavenging.

This subclass is indented under subclass 125. Subject matter wherein means are provided to modify one
or more temperatures within the tube, e.g., to decrease the operating
temperature of the rotor bearings to prevent them from seizing.

(1)Note. Also included is subject matter having means comprising
evaporable metal for transferring heat away from the focal spot
to lower the maximum instantaneous local temperature on the target itself.

This subclass is indented under subclass 127. Subject matter wherein a temperature (usually the bearing
temperature) is modified through the use of means to diminish the
rate of heat transfer in a specific direction.

This subclass is indented under subclass 121. Subject matter including means for decreasing local potential
gradients such as would result in puncturing of the envelope, e.g.,
the means is typically a coating on the surface of the envelope,
the resistivity of the coating being just low enough to drain off
electrical charges which would otherwise accumulate during the operation
of the tube.

This subclass is indented under subclass 121. Subject matter provided with means for absorbing secondary
electrons and/or unwanted photons, and X-ray tubes having
a window in the envelope of the tube which passes a broader spectrum
of X-ray radiation than is passed by the remainder of the envelope.

(1)Note. Included in this subclass, for example, are X-ray tubes
having an envelope made of a glass which transmits only "hard" X-rays
and which has a window made of a material that will transmit "soft"
X-rays.

(2)Note. A typical secondary screen is a hood surrounding the
target with an entrance aperture for primary electrons and an exit
aperture for desired X-rays.

This subclass is indented under subclass 141. Subject matter wherein the cooling means is in the form
of a solid and acts to remove heat by conduction from or blocks
the passage of heat to some region of the tube.

This subclass is indented under subclass 145. Subject matter including means to cause the beam of X-rays
to sweep over a selected area by sequentially passing small portions
of a large beam while blocking all other portions, e.g., an X-ray
opaque Nipkow disk.

(2)Note. Beam masking devices positioned on or adjacent an irradiated
object so as to protect the object are considered radiation shields
and are classified in Class 250, Radiant Energy, subclass 515.1.

This subclass is indented under subclass 147. Subject matter wherein the collimator is formed of a large
number of small apertures, e.g., arranged in the form of a honeycomb, which
apertures are employed simultaneously.

This subclass is indented under subclass 150. Subject matter wherein the aperture in the collimator is
bounded by movable leaves of X-ray opaque material and these leaves
are each movable along straight lines.

This subclass is indented under subclass 150. Subject matter wherein the aperture in the collimator is
bounded by movable leaves of X-ray opaque material and these leaves
are each movable about pivot points.

This subclass is indented under subclass 145. Subject matter including a plurality of X-ray opaque elements
arranged in the form of a grid and used to prevent the passage therethrough
of X-rays coming from other than a desired direction.

This subclass is indented under subclass 162. Subject matter including means of known dimensions which
are at least partly opaque to X-rays placed on or near the object
at known distances from each other such that they appear in the
final image of the object and whose images may be used to calculated
distance or dimensions within the object.

This subclass is indented under subclass 167. Subject matter providing for the sequential supply of unexposed
X-ray plates or cassettes to an X-ray exposure station and for the
subsequent removal therefrom of exposed plates or cassettes.

This subclass is indented under subclass 167. Subject matter providing for the sequential supply of unexposed
X-ray films or film packs to an X-ray exposure station and for the
subsequent removal therefrom of exposed films or film packs.

This subclass is indented under subclass 175. Subject matter including means such as a fluorescent screen
or a television system which provides a visual presentation of the
X-ray image being recorded photographically.

This subclass is indented under subclass 182. Subject matter wherein the cassette includes some means
to modify the radiation entering the cassette such as antiscatter
means, filters, or intensifier screens.

This subclass is indented under subclass 185. Subject matter including means for holding the film in intimate
contact with a support surface such as foam pads, pressure plates,
or cassette evacuation means.

This subclass is indented under subclass 189. Subject matter wherein the detector exhibits an image of
the object by means of a material which fluoresces in response to
the X-radiation being transmitted through the object.

This subclass is indented under subclass 205. Subject matter including the projection of a beam of light
in a direction such that by monitoring the position where the light
strikes the object, alignment may be achieved.

This subclass is indented under subclass 204. Subject matter including means designed to test an X-ray
device for proper operation or to aid in the adjustment of the device
for operation within desired characteristics.

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